Yeah, I'm sure the guys in the road bike section have a lot more to say about mountain bike mechanical disk brakes than the guys in the mountain bike forum...

I've got the BB7s, never owned or tried the BB5s. I love the BB7s and find them very easy to adjust. I'll second the comments about the levers. I had a set of cheap levers and the brakes didn't have a great feel to them. I upgraded to the Avid adjustable levers and now the brakes feel awesome.